Carrying 12 copies of "Roots," two young men rushed out of the Kramerbooks and Afterwords shop in downtown Washington without paying. In College Park, workers at the Maryland Book Exchange followed a young man to his car, where they found 25 stolen copies of "Roots."

Thieves who have stolen copies of "Roots" from bookstores and libraries in cities across the country are selling the $12.50 book for $5 and up on buses, subways and street corners.

This underground market is one indication of the phenomenal success of Alex Haley's saga of an American black family.

"Roots" is being sold legitimately not only in bookstores but in places where hard-cover books are rarely found - on the counters of liquor stores, in drugstores and in supermarkets.

The book is going into its 14th printing since its publication last October. Soon there will be a million copies distributed across the nation. On a single day last week 67,159 copies were shipped from Doubleday's warehouses to fill orders.

the book was successful even before the spectacularly popular television showing on ABC for eight consecutive nights last week. But since then, both the legitimate and underground markets for the books have expanded beyond precedent.

Book distributors in the metropolitan area have had trouble stocking of the book to meet the demands of book buyers.

"We can't keep them in stock," said Pat Cox, of Ingram book distributors, in Jessup, Md. "We've got thousands of back orders waiting to be filled."

"The book has touched a nerve in Washington," said Fred Eisenhart, book buyer for RPM. "We're sold out. "We've sold larger quantities of this book than any other book in the last year and a half."

Eisenhart said RPM has sold 2,000 copies of the hardbook version of the book since the television version of "Roots" ended.

Before the show went on television RPM sold only 1,800 copies of the book in the three weeks after Christmas.

Book distributors said no book sin recent memory rival Roots as a moneymaker.

"Jonathan Livingston Seagull," "Love Story," sand maybe "Everything You Wanted to Know About Sex" came close to demanding as large a number of books out of us," said Jose Gonzales, assistant manager of District distributors. "But I can't get enough copies of 'Roots' - I sold out again today."

Gonzales' company has been placing "Roots" in Dart drugstores and Drug Fair as well as in Giant Food stores. Those outlets usually sell only paperbacks.

"I could put that book in any location and it would sell," said Gonzales.

Peddlers have been seen selling the book in a Metrobus on 16th Street, on the corner of F Street, and elsewhere in the Washington area.

Mostof these books have been stolen from retail outlets rather than from warehouses. In the Washington area at least five bookstores have apprehended shoplifters taking quantities of the book.Most of those who have been caught simply picked up an armful and walked out the front door, as if in defiance of store managers.

In New York a display window of the Doubleday Book Store on 5th Avenue was broken and all the copies of "Roots" in it taken. The store manager, Kent Livingston, says "Roots" is "the most ripped off book I've ever seen. People are coming in with shopping bags and carting them off."

Last week at Kramerbooks and Afterwords, 1347 Connecticut Ave, NW, two young men picked up armfuls of the book and walked out. Two men who work at the store caught up with them on Connecticut Avenue.

"They asked them where they were going without paying for the books," said Bill Kramer, owner of the store. "They asked them to give us our books back."

According to Kramer the two men said they took the books to protest white exploitation of a black man's work.

"They gave us the books back and went off," said Kramer. "They asked if they coule keep one. We said no."

Several stores in the Washington area suspect that they have been losing copies of "Roots" to shoplifters, but have no way of knowing exactly how many. The manager of one downtown store said simply, "I wouldn't be surprised. I have sold - or am missing - 200 copies in the last couple of weeks."

Other books have been conspicuous favorites of shoplifters in the past. Last Christmas several stores in the Washington area lost copies of Leni Riefenstahl's book of photographs, "The People of Kau," and New York stores have reported losses of Wilfrid Sheed's "Muhammad Ali."

Susan Lemoon, a buyer for RPM Distributors, says she can remember only a couple of other examples, and they were paperbacks. "One was Abbie Hoffman's 'Steal This Book.' The other, and this is going way back, was 'The Autobiography of Malcolm X'" which was coauthored by Alex Haley in 1963.

Sales of a million volumes would make "Roots," after only four months on the stands, one of the best-selling hard-cover books of all time. The trade publication Publishers Weekly considers any book that sells more than 750,000 copies to bein that category. "Gone With the Wind," for instance, has sold 5,190,000 hard-cover copies since 1936. "The Better Homes and Gardens Cookbook" leads the most recent list (which excludes various editions of the Bible) with 18,694,976 copies sold since 1930.